This R21 exploratory project will examine frontal white matter, executive functioning and treatment outcomes in adolescents with alcohol use disorders (AUDs). The project will specifically focus on the measurement and integration of constructs from three domains: (1) frontal white matter organization determined by diffusion tensor imaging (DTI), (2) executive functioning, measured by neuropsychological tests and functional assessments, and (3) alcohol and other substance involvement assessed monthly over a one-year period. Utilizing the resources of an on-going project on the substance involvement outcomes of adolescents in treatment for AUDs compared to a community control group (i.e., Recovery Project; R01AA014357; PI: Chung), the project will recruit 75 subjects (50 with AUDs, 25 controls) to participate in neuropsychological and neuroanatomical assessments at treatment initiation and a one-year follow-up. The Recovery Project conducts monthly substance use assessments, yielding an exceptionally detailed description of substance use trajectories in the intervening year. The neurodevelopmental assessment will include neuropsychological tests and neuroanatomical characterization by both conventional morphometric magnetic resonance imaging (MRI) and DTI. We anticipate that one-year outcome data will identify AUD subjects essentially achieving abstinence, AUD subjects relapsing to substantial continued alcohol involvement, and control subjects with minimal alcohol use. The hypothesized model specifies that alcohol abstinence will predict increases in white matter organization in frontal white matter tracts and correlated improvements in executive functioning. The R21 project will determine feasibility, provide estimates for statistical power and sample size calculations and initiate a collaboration between our programs in Pittsburgh and Minnesota. The study will thus determine the feasibility of demonstrating improvements in white matter integrity among adolescents with AUDs successfully completing treatment utilizing a prospective design and a contrasting relapsing AUD group and a community control group.